A grinding apparatus for machining a workpiece (6), including an apparatus frame (2) supporting a grinding station (3) with a number of grinding heads (4) with associated grinding elements (5) arranged such that the grinding elements (5) are in contact with one surface (7) of the workpiece at the passage of the workpiece through the grinding apparatus (1), and an endless conveying means (8) for the grinding heads (4), and a roller table (9) for supporting the workpiece (6), where the grinding apparatus (1) includes a further grinding station (10) with grinding heads (4) arranged such that the grinding elements (5) are in contact with the opposite surface (11) of the workpiece at the passage of the workpiece across the roller table (9), where the roller table includes a first (12) and a second set of rollers (13), and where there is an interspace (14) between two set of rollers (12, 13), allowing passage of the workpiece between the two set of rollers (12, 13), wherein spacing (15) between individual rollers (16) in each of the two sets of rollers (12, 13) is arranged such that a plurality of the rollers (16) from each of the two sets of rollers (12, 13) are simultaneously in contact with the opposing surfaces (7, 11), where a first grinding station (3) is provided between two succeeding rollers in the first set (12) and a second grinding station (10) is provided between two succeeding rollers in the second set (13).